Box type cap for excavating teeth



Aug. 4, 1936.

H. L. MORRISON BOX TYP E CAP FOR EXCAVATING TEETH File d Dec. 10, 1954 Patented Aug. 4 1936 UNITED STATES I PATENT OFFICE a I v v 2,050,014 Y I BOX TYPE CAP FOR EX CAVATING TEETH Barry L. Morrison, Los Angeles, Calif., assignor to American Manganese Steel Company, Chlcago Heights, 111., a corporation of Maine Application December 10, 1934, Serial No. 756,722

6 Claims. (Cl. 37-142) This invention relates to teeth which are applied to dippers, shovels and other excavating implements, and particularly to teeth which, for the sake of prolonging their life, are provided with replaceable caps mounted upon the teeth through means of forwardly projecting horns on the teeth fitting in rearwardly presented sockets of the caps. The object of the present invention is to provide a replaceable cap preferably constructed with symmetrically identical upper and lower portions that adapt it to be reversed in position uponithe horn of the tooth, and so designed that it may be-made with sufllcient strength to with stand the severe physical conditions which it encounters in use without making the cap unduly heavy and which, by reason of its novel structural conditions, will be of superior digging capacity.

The invention proceeds upon the principle of providing a cap of the kind usually referred to as box type, by reason of utilizing the rearwardly presented complete socket as a means of mounting it in position, in which the wall that resists tipping of the cap upon the tooth is arched inwardly from side to side of the tooth so that the correspondingly formed face on the horn which receives this inwardly arched wall will distribute the forces through which it sustains the cap in a more advantageous way and, therefore, permit such wall of the cap to be made with relatively light dimensions; the inwardly arched wall being further advantageous in that it provides a cavity in the face through which the cap lifts the excavated material and thereby prolongs digging efficiency of the cap, and provides a recess which will greatly relieve the wear upon the securingpin.

In the accompanying drawing 40 Figure 1 is a vertical longitudinal section of a portion of -a dipper front with a multiple part tooth mounted thereon and including one illustrative embodiment of the present invention.

Figure 2 is a top plan view on an enlarged scale of the novel construction of cap employed in Figure 1.

Figure 3 is a vertical longitudinal section of the cap shown in Figure 2.

Figure 4 is an elevational view of the rear open end of the cap, with the horn in section.

Figure 5 is a section on the line Bz-lix of Figure 3; and

Figure 6 is a perspective view of the cap.

A indicates a portion of the lip or digging front of any standard type of dipper or other excavating implement; B is the base portion of a tooth riveted on said lip; C indicates a replaceable forward portion of a tooth terminating in a cap-receiving horn D; and E represents the cap which is designed to be reversibly and re- 51 placeably applied to said horn.

Cap E is constructed with a rearwardly presented horn-receiving socket I, vertically tapered forwardly from its open end and defined by side I walls 2 and symmetrically similar'upper and 10 lower walls 3. The walls 3 are arched inwardly from side to side of the socket portion of the tooth cap to provide a cavity 4 which extends forwardly with decreasing depth near the digging end of the tooth, and it is to be understood 15 that the wedge D which receives the socket! is concaved on its upper and lower faces to receive such inwardly arched walls. Arching the walls as describeddevelops uponthe cap outer side edges 5, the defining faces of which meet at 20 angles less than 90, while the cavity t, except at the side edges of the cap, reduces the thickness of the digging point so that it may wear away to a considerable extent without getting unduly dull. Inwardly arching the walls resists 25 outward bulging, renders the cap self centering and resistant to side weaving under tipping forces in either vertical direction, and develops interior angular pockets 6 of less than 90 which tend to localize lifting stress in close proximity to the side walls 2 and put the top and bottom walls 3 under shear stresses very close to the said side walls.

i represents lugs located in the cavities t in 0 position to prevent material from destroying the overturned ends of the securing pin 9 that passes through the apertures 8 of the cap and the corresponding slot it) in the horn D.

The present invention contemplates three structural novelties in a digging tooth having a replaceable cap of the box type, namely, a horn upon which the cap is mounted embodying the novel feature of a hollowed or trough-shaped surface (which, while accommodating an inwardly arched transverse wall of the cap socket that receives the horn, performs its own function of localizing the seats through which the horn receives the cap adjacent the side walls of the cap, and which function would not be performed with a cap having straight upper and lower confines; secondly, a cap per se having at least its upper wall and, if made reversible, both its upper and lower walls arched inwardly to provide the outer cavity and the inwardly presented arch with the several advantages herein ascribed to said structure; and thirdly, the combination of a hollow faced horn with inwardly arched cap confine-whereby the cap is allowed'to perform the further function of developing a more extensive seat upon the nose under both upward and downwardtipping forces on the cap, and an internal socket confine which, being reentrant, opposes lateral weaving motion and reduces deterioration of the pin that holds the cap in place.

The cap bonstitutes in itself an inventive entity or new article of manufacture as a replacement part, and is applicable only to a projection having surfaces to which it may conform; but'the horn or projection, while exercising a useful function by reason of its form, is not dependent upon the novel form of cap but may be supplied with a straight wall cap if necessary in keeping the implement in useful condition.

2. A cap of the box type for the digging teeth of an excavating implement, said cap having a rearwardly presented socketdeilned by opposite side walls and upper and lower transverse walls extending between said side walls, at least one of the transverse walls being arched inwardly from side to side. and providing'longitudinally extending acute angular horn receiving seats where the side walls and concave wall meet.

3. A box type cap for digging teeth, constructed with a rearwardly opening tooth-receiving socket defined by side walls in substantially vertical planes and transverse walls; said transverse walls converging forwardly to develop a wedge-shape in said socket; and at least one of the transverse socket forming walls of the socket being arched inwardly between the side walls and providing a concave outer surface a convex inner wall and acute angular internal longitudinal bearing corners.

4. In an excavating implement, a tooth of the type employing a replaceable box type cap; said tooth being constructed with a cap-receiving horn having a face that is hollowed from side to side, leaving thereon substantially acute angular longitudinal cap-receiving seats adiacent its sides.

5. A tooth as described in claim 4, in which both the upper and lower-faces are constructed as described therein.

6. A tooth for excavating machines having a horn for receiving a replaceable cap of ,box type; said horn having sides in substantially vertical planes, upper and lower transverse faces extending between said sides and converging forwardly to develop a wedge, and at least one of said transverse faces being hollowed between the sides to provide the socket with. a longitudinally straight but transversely convex inner confine and thereby localize the bearing of the cap mainly at the sides of the horn.

. v HARRY L. MORRISON. 

